Electronic equipments such as mobile phones are usually equipped with a rechargeable battery that can be charged through a power adapter.
Upon charging, the power adapter converts alternating current (AC) to direct current (DC) with specified voltage and supplies DC to electronic equipments. In the power adapter and the electronic equipment, an electronic interface is typically provided respectively. Electrical connection with a charging cable can be achieved through the electronic interface, whereby the electronic equipment can be charged through the charging cable.
Electrical connection between electronic interfaces is achieved via contact of a metal contact sheet. Because of thermal effects of resistance, heat is generated at the metal contact sheet when charging current flows through. Large charging current or high charging voltage may cause high temperature of the electronic interface; in such a condition, device damage or even an explosion may occur, which can affect the security of charging.